1. 30 Oct, 2011 1 commit
  2. 03 Aug, 2011 3 commits
  3. 24 Jul, 2011 1 commit
  4. 22 Jun, 2011 1 commit
  5. 26 May, 2011 1 commit
  6. 23 May, 2011 3 commits
  7. 14 Apr, 2011 1 commit
  8. 05 Jan, 2011 4 commits
  9. 25 Oct, 2010 2 commits
  10. 24 Aug, 2010 1 commit
    • Martin Schwidefsky's avatar
      [S390] fix tlb flushing vs. concurrent /proc accesses · 050eef36
      Martin Schwidefsky authored
      
      
      The tlb flushing code uses the mm_users field of the mm_struct to
      decide if each page table entry needs to be flushed individually with
      IPTE or if a global flush for the mm_struct is sufficient after all page
      table updates have been done. The comment for mm_users says "How many
      users with user space?" but the /proc code increases mm_users after it
      found the process structure by pid without creating a new user process.
      Which makes mm_users useless for the decision between the two tlb
      flusing methods. The current code can be confused to not flush tlb
      entries by a concurrent access to /proc files if e.g. a fork is in
      progres. The solution for this problem is to make the tlb flushing
      logic independent from the mm_users field.
      Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
      050eef36
  11. 27 May, 2010 1 commit
  12. 30 Mar, 2010 1 commit
    • Tejun Heo's avatar
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking... · 5a0e3ad6
      Tejun Heo authored
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
      
      percpu.h is included by sched.h and module.h and thus ends up being
      included when building most .c files.  percpu.h includes slab.h which
      in turn includes gfp.h making everything defined by the two files
      universally available and complicating inclusion dependencies.
      
      percpu.h -> slab.h dependency is about to be removed.  Prepare for
      this change by updating users of gfp and slab facilities include those
      headers directly instead of assuming availability.  As this conversion
      needs to touch large number of source files, the following script is
      used as the basis of conversion.
      
        http://userweb.kernel.org/~tj/misc/slabh-sweep.py
      
      
      
      The script does the followings.
      
      * Scan files for gfp and slab usages and update includes such that
        only the necessary includes are there.  ie. if only gfp is used,
        gfp.h, if slab is used, slab.h.
      
      * When the script inserts a new include, it looks at the include
        blocks and try to put the new include such that its order conforms
        to its surrounding.  It's put in the include block which contains
        core kernel includes, in the same order that the rest are ordered -
        alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
        doesn't seem to be any matching order.
      
      * If the script can't find a place to put a new include (mostly
        because the file doesn't have fitting include block), it prints out
        an error message indicating which .h file needs to be added to the
        file.
      
      The conversion was done in the following steps.
      
      1. The initial automatic conversion of all .c files updated slightly
         over 4000 files, deleting around 700 includes and adding ~480 gfp.h
         and ~3000 slab.h inclusions.  The script emitted errors for ~400
         files.
      
      2. Each error was manually checked.  Some didn't need the inclusion,
         some needed manual addition while adding it to implementation .h or
         embedding .c file was more appropriate for others.  This step added
         inclusions to around 150 files.
      
      3. The script was run again and the output was compared to the edits
         from #2 to make sure no file was left behind.
      
      4. Several build tests were done and a couple of problems were fixed.
         e.g. lib/decompress_*.c used malloc/free() wrappers around slab
         APIs requiring slab.h to be added manually.
      
      5. The script was run on all .h files but without automatically
         editing them as sprinkling gfp.h and slab.h inclusions around .h
         files could easily lead to inclusion dependency hell.  Most gfp.h
         inclusion directives were ignored as stuff from gfp.h was usually
         wildly available and often used in preprocessor macros.  Each
         slab.h inclusion directive was examined and added manually as
         necessary.
      
      6. percpu.h was updated not to include slab.h.
      
      7. Build test were done on the following configurations and failures
         were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
         distributed build env didn't work with gcov compiles) and a few
         more options had to be turned off depending on archs to make things
         build (like ipr on powerpc/64 which failed due to missing writeq).
      
         * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
         * powerpc and powerpc64 SMP allmodconfig
         * sparc and sparc64 SMP allmodconfig
         * ia64 SMP allmodconfig
         * s390 SMP allmodconfig
         * alpha SMP allmodconfig
         * um on x86_64 SMP allmodconfig
      
      8. percpu.h modifications were reverted so that it could be applied as
         a separate patch and serve as bisection point.
      
      Given the fact that I had only a couple of failures from tests on step
      6, I'm fairly confident about the coverage of this conversion patch.
      If there is a breakage, it's likely to be something in one of the arch
      headers which should be easily discoverable easily on most builds of
      the specific arch.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Guess-its-ok-by: default avatarChristoph Lameter <cl@linux-foundation.org>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
      5a0e3ad6
  13. 24 Mar, 2010 1 commit
  14. 08 Mar, 2010 2 commits
  15. 26 Feb, 2010 4 commits
  16. 13 Jan, 2010 2 commits
  17. 29 Oct, 2009 3 commits
    • Heiko Carstens's avatar
      [S390] smp: fix sigp sense handling · b3dcf3de
      Heiko Carstens authored
      
      
      sigp sense only returns the status of a cpu if it is non zero. If the
      status of the sensed cpu is all zeros condition code 0 (accpeted) is
      set and no status bits are returned.
      The current code however assumes that a status was returned and tests
      bits in it. This means uninitalized data is accessed with random
      results.
      Worst case is that the code that checks if cpu is offline on cpu
      hotplug assumes that the target cpu is offline while it is still
      running. This leads potentially to memory corruption since resources
      that are still needed by the target cpu will be freed and could be
      resused while still in use.
      Signed-off-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
      Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
      b3dcf3de
    • Heiko Carstens's avatar
      [S390] smp: fix sigp stop handling · f8501ba7
      Heiko Carstens authored
      
      
      According to the architecture a cpu must not necessarily enter stopped
      state after completion of a sigp instruction with "stop" order code.
      So remove the BUG() statement after self sending sigp stop to avoid
      that it ever gets reached.
      Also add a sigp busy check to make sure that the order gets delivered.
      Signed-off-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
      Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
      f8501ba7
    • Heiko Carstens's avatar
      [S390] smp: fix prefix handling of offlined cpus · 4f8048ee
      Heiko Carstens authored
      
      
      Offlined cpus still have valid prefix register contents. Dumpers
      will store the register contents of a cpu to the location where its
      prefix register points to.
      For offlined cpus the area (lowcore) has been freed and the dumper
      would write the uninteresting contents of the offline cpu to a memory
      location which might be in use by some other component and destroy
      valueable information.
      To fix this set the prefix register of offline cpus to absolute
      address zero again. This prevents the current dumpers to write to
      random memory locations.
      Signed-off-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
      Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
      4f8048ee
  18. 24 Sep, 2009 1 commit
  19. 22 Sep, 2009 2 commits
  20. 11 Sep, 2009 2 commits
  21. 24 Jul, 2009 1 commit
    • Heiko Carstens's avatar
      [S390] vdso: fix per cpu area allocation · 3a6ba460
      Heiko Carstens authored
      
      
      vdso per cpu area allocation in smp_prepare_cpus() happens with GFP_KERNEL
      but irqs disabled. Triggers this one:
      
      Badness at kernel/lockdep.c:2280
      Modules linked in:
      CPU: 0 Not tainted 2.6.30 #2
      Process swapper (pid: 1, task: 000000003fe88000, ksp: 000000003fe87eb8)
      Krnl PSW : 0400c00180000000 0000000000083360 (lockdep_trace_alloc+0xec/0xf8)
      [...]
      Call Trace:
      ([<00000000000832b6>] lockdep_trace_alloc+0x42/0xf8)
       [<00000000000b1880>] __alloc_pages_internal+0x3e8/0x5c4
       [<00000000000b1b4a>] __get_free_pages+0x3a/0xb0
       [<0000000000026546>] vdso_alloc_per_cpu+0x6a/0x18c
       [<00000000005eff82>] smp_prepare_cpus+0x322/0x594
       [<00000000005e8232>] kernel_init+0x76/0x398
       [<000000000001bb1e>] kernel_thread_starter+0x6/0xc
       [<000000000001bb18>] kernel_thread_starter+0x0/0xc
      
      Fix this by moving the allocation out of the irqs disabled section.
      Reported-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
      Signed-off-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
      Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
      3a6ba460
  22. 22 Jun, 2009 1 commit
  23. 16 Jun, 2009 1 commit